The discharge characteristics of single-units in the cat lateral superior olive (LSO) will be studied. Two experimental paradigms will be followed. In the first, the nature of the ipsilateral inputs will be examined by functionally isolating the nucleus from its contralateral input. In the second, the neuronal response to dichotic transient sounds will be explored. These investigations will attack the general neurophysiological problems of excitatory-inhibitory interactions as well as the more specific functions the LSO serves in the analysis of binaural hearing. Particular attention will be given to its possible role in the detection of the short interaural-time differences involved in the localization of transients. Metal microelectrodes will record extracellular neuronal activity. A small general purpose computer will assist in stimulus control, data acquisition, data storage, and analysis.